As the massive manhunt for the Boston Marathon bombing suspect played out on Friday, broadcast networks revamped their programming schedules to provide additional coverage during Friday prime time.

CBS announced that it will pre-empt "Vegas" for a 9 p.m. news special titled "CBS News Special Report: Boston Bombers" with Scott Pelley serving as anchor.

"Vegas" will move to 8 p.m. Saturday.

In addition, ABC announced a special live report during its usual "20/20" slot at 10 p.m. Elizabeth Vargas will anchor from Boston. NBC will likewise use its "Rock Center with Brian Williams" slot at 10 p.m. for coverage of developments from Massachusetts.

Meanwhile, the cable news stations, including Fox News, CNN, and MSNBC, will continue to follow events around the clock.